In the first stages of its life, Panulirus cygnus eat plankton that is found close to the surface of the ocean.
As the lobsters get older and move to the reefs, they also change their feeding habits. They begin to go out at night and search for food. In one night, a lobster is said to cover a mile or more a night looking for food. Panulirus cygnus are considered to be omnivorous, eating both animal and plant materials. They eat mollusks, worms, crabs, clams, sea urchins, slow flounder, seaweed, and seagrasses. A lobster will even eat another lobster if they have the chance. In cages lobsters can be cannibalistic, but this has never been seen in the wild.
Animal Foods: mollusks; terrestrial worms; aquatic crustaceans
Plant Foods: macroalgae
Foraging Behavior: stores or caches food
Primary Diet: omnivore